rtadvctl: Use nitems(foo) instead of sizeof(foo)/sizeof(foo[0])

Pull Request: #888
Signed-off-by: Elyes Haouas <ehaouas@noos.fr>

usr.sbin/rtadvctl/rtadvctl.c

@@ -27,8 +27,8 @@
  *
  */
 
+#include <sys/param.h>
 #include <sys/queue.h>
-#include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/un.h>
@@ -137,7 +137,7 @@ usage(void)
 {
 	int i;
 
-	for (i = 0; (size_t)i < sizeof(dtable)/sizeof(dtable[0]); i++) {
+	for (i = 0; (size_t)i < nitems(dtable); i++) {
 		if (dtable[i].dt_comm == NULL)
 			break;
 		printf("%s\n", dtable[i].dt_comm);
@@ -172,7 +172,7 @@ main(int argc, char *argv[])
 	if (argc == 0)
 		usage();
 
-	for (i = 0; (size_t)i < sizeof(dtable)/sizeof(dtable[0]); i++) {
+	for (i = 0; (size_t)i < nitems(dtable); i++) {
 		if (dtable[i].dt_comm == NULL ||
 		    strcmp(dtable[i].dt_comm, argv[0]) == 0) {
 			action = dtable[i].dt_act;